1. Field of the Invention
The present invention relates generally to the field of electrical connectors. In particular, the present invention relates to coaxial RF connectors.
2. Background Art
Electrical connectors provide couplings between electronic elements and/or devices. Many different types of electrical connectors exist and have been used to provide removable electrical connections between electronic elements and devices. On such type is RF (radio frequency) connectors.
Bayonet mechanisms are one way of securing such removable RF electrical connectors. One type of removable or separable electrical connector having a bayonet mechanism is known as a BNC or Bayonet Neil-Concelman mating connector pair. BNC mating connector pairs facilitate attachment of coaxial electrical cables to electronic elements or devices. Typical BNC mating connector pairs include a jack-side connector mounted to an electronic device or element and a plug-side connector connected to a cable. The jack-side connector typically includes a tubular cylindrical housing and a socket formed in a central location of the housing. The plug-side connector typically includes a tubular cylindrical connector body having a central contact formed in a central location of the connector body. The central contact of the plug-side connector is inserted into the socket of the jack-side connector and the connector body of the plug-side connector is inserted into the housing of the jack-side connector.
The jack-side connector also includes outwardly extending lugs formed on the outer surface of the housing. The plug-side connector includes a bayonet sleeve rotatably mounted on the outer surface of the connector body. The bayonet sleeve includes slots, which are typically J-shaped (J-slots), to mate with the lugs on the jack-side connector. The J-slots include an initial portion and a terminal portion. To connect the BNC mating connector pair, the slots in the bayonet sleeve first receive the lugs into the initial portion of the J-shaped slots, such that the mating connector pair is in a position of partial engagement. The bayonet sleeve is then rotated relative to the jack-side connector until the lugs slide into the terminal portion of the J-shaped slots. The mating connector pair is now in a fully engaged position, where the lugs are held and locked into the terminal portion of the J-shaped slots.
U.S. Pat. No. 4,037,909 to Trompeter et al. and U.S. Pat. No. 3,708,781 to Trompeter, which are herein incorporated by reference in their entirety, each disclose full-size BNC mating connector pairs. Further, BNC mating connector pairs are commercially available from Trompeter Electronics, Inc., Westlake Village, Calif. A common use of the Trompeter 75 ohm BNC mating connector pair is for telephone company central office DS3 applications. Full-size BNC mating connector pairs also see high volume use in the broadcast industry for providing high bandwidth connections between television broadcast equipment.
The twist-lock connection of the bayonet mechanism is a central feature of BNC connector pairs, and provides a convenient and reliable means for electrically connecting various electronic elements and devices. BNC connector pairs allow a reliable electrical connection to be made without the danger of the jack-side and plug-side connectors gradually working loose or becoming inadvertently unplugged.
The bayonet mechanism of BNC mating connector pairs provides a positive engagement between jack-side connectors and plug-side connectors. This positive engagement allows a user to determine whether a jack-side connector is fully engaged with a plug-side connector by attempting to manually rotate the bayonet sleeve (e.g., using his or her fingers). If substantial resistance is encountered, then the mating connector pair is fully engaged.
Large numbers of full-size BNC mating connector pairs are often positioned in close proximity (both vertically and horizontally) on network elements. Increased market demand for telephone lines (for voice, fax and data traffic) has caused additional crowding in telephone company central offices. It is desired to increase the density of connections on, for example, digital cross connect modules. However, the mechanical footprint of the standard BNC connector hinders further increases in connection densities.
Connectors, such as the SMB connector, with smaller footprints might be used, but they lack certain advantages (e.g., the bayonet locking feature and field crimpability) of BNC connectors, which have become an industry standard. Therefore, the present inventors have recognized that, what is needed, is a connector having the advantages of the BNC connector but having a smaller footprint to allow an increase in connector population density on, for example, network elements such as an OC-48 multiplexer or a DSX (digital cross connect).
Another problem that occurs when multiple mating connector pairs are positioned in close proximity is that it is often not possible for a user to look at the mating connector pairs from a viewpoint that allows visual inspection of the relative positioning between the lug and the J-shaped slot to confirm full engagement. Consequently, it is often difficult to manually determine whether a jack-side connector is fully engaged with a corresponding plug-side connector.
Thus, a need also exists for an improved mating connector pair that provides visual indication of the engagement position of the plug-side connector relative to the jack-side connector when the plug-side connector is fully engaged with the jack-side connector.